JP3319148B2 - Deteriorated battery detector for assembled batteries - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembled battery comprising a combination of a plurality of cells constituting a power source for an electric vehicle, for example, so that deterioration of each of the cells constituting the assembled battery can be detected. The present invention relates to a device for detecting a deteriorated battery of an assembled battery.

[0002]

2. Description of the Related Art In an electric vehicle, an electric motor is used as a driving source, and an assembled battery in which a large number of cells are connected in series is used as a power source for the driving motor. As a unit cell constituting such an assembled battery, a lead battery is generally used, but if a deteriorated battery is mixed in the unit cell constituting such an assembled battery, The performance of the entire battery pack is reduced. For this reason, a deteriorated cell is quickly detected from many assembled batteries,
It is necessary to take measures such as replacing the deteriorated battery.

Here, there is no means for directly detecting the deterioration of each unit cell.
As disclosed in Japanese Patent Publication No. 59, the terminal voltage of each unit cell is measured and compared with a specified voltage for judging that the cell is normal. Degraded batteries are detected by measuring their specific gravity.

However, in electric vehicles and the like, for example,
An assembled battery is composed of a combination of zero or more single cells. Therefore, it is necessary to take out terminals from each of such multiple single cells and measure the voltage. In order to measure the specific gravity, the apparatus becomes very large. Therefore, the cost of the device for detecting the deteriorated battery increases.

[0005] The technology disclosed herein is intended mainly for a battery mounted in an automobile using an internal combustion engine as a power source, and has a certain degree of operation such as operating a starter motor when the internal combustion engine is started. It is effective when it is clear that a large current is discharged.

However, in the case of an electric vehicle, almost no current flows when the engine is started, and the discharge current from the battery power source changes in the running state. In the device disclosed in Japanese Patent Application Laid-Open No. 200057, it is not possible to accurately detect the deterioration state of each of the cells constituting the assembled battery. Further, in such an apparatus, a processing circuit is required for each cell, and when the number of cells is increased as in an electric vehicle, the insulation between the processing circuits set for each cell is reduced. If necessary, the circuit becomes large.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is an object of the present invention to easily detect a deteriorated battery from a large number of cells constituting an assembled battery in, for example, an automobile dealer or a maintenance shop. It is an object of the present invention to provide an assembled battery deteriorated battery detection device capable of inspecting an assembled battery in an on-vehicle state without considering the number of cells and the connection status that differ for each vehicle.

[0008]

SUMMARY OF THE INVENTION The deterioration battery detection of the assembled battery according to the present invention, is set to a power line which is output from the assembled battery constituted by a plurality of unit cells which are optionally connected
And the output current from the battery pack flowing through this power line is measured.
Current detecting means for determining
Multiple clips that are arbitrarily clipped to each terminal
Multiple measurement terminals composed of lead-out terminals
Select any measurement terminal from among multiple measurement terminals
Means. Further, the voltage measuring means may be
Therefore, the voltage is measured through the selected measurement terminal
One measurement terminal and the other measurement terminals
Measure the terminal voltage between them, and based on the measured value,
The connection order of each of the plurality of cells is determined, and the determination is made.
Measure the open terminal voltage of each cell based on the
Can be specified. Then, the components constituting the battery pack
Measurement of the open terminal voltage when the number of cells is fully charged,
Terminal voltage measurement means at full charge, which is measured and stored by means
Driving the load connected to the battery pack to detect the current
Output means for measuring the discharge current from the battery pack,
Current value judgment to judge that the value is within the set range
Means, and the discharge current from the battery pack is
In the state where it is determined that the electric current is within the set range, the discharge of each of the unit cells
Hour terminal voltage is measured and stored by the voltage measuring means.
Terminal voltage measuring means at the time of discharge. Where the memory
Terminal voltage at full charge and terminal voltage at discharge
Is compared with the set specified voltage, and based on the comparison result,
The battery that has deteriorated is identified.

[0009]

In the battery cell deterioration detecting apparatus constructed as described above, the measuring terminals are randomly connected to a plurality of cells mounted on the vehicle by a clip terminal structure or the like. Then, the voltage measuring means is connected to the selected measuring terminal, and the voltage between arbitrary terminals is sequentially measured and compared, and the connection order of the unit cells corresponding to the measuring terminals is obtained from the arrangement of the measured voltage values. Thus, the open terminal of each unit cell can also be specified. If the open terminal of each cell is identified in this manner, the terminal voltage of each cell is measured and stored in the fully charged state of each cell, and the state of discharge from the assembled battery is measured. The terminal voltage at the time of discharge of each cell is measured in a state confirmed by the current detecting means, and the terminal voltage at the time of discharge is measured and stored. Therefore, for example, preliminary detection of a deteriorated battery is performed based on the open terminal voltage at the time of full charge, and in the unit cell considered to be the preliminarily detected deteriorated battery, the open terminal voltage at the time of full charge and the discharge terminal The voltage drop of each cell at the time of discharge is obtained from the difference from the voltage, and if it is determined that the voltage drop is equal to or more than a predetermined specified value, it is determined that the cell has deteriorated.
Therefore, the deteriorated battery is reliably detected by connecting the measuring terminals to the cells mounted on the automobile or the like at random with very simple equipment, which has a great effect on the efficiency of the maintenance work of the electric automobile. Be demonstrated.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of the electric vehicle.
11 and a deteriorated battery detection circuit 12.
The electric vehicle 11 is equipped with a battery power source 13 as a power source. The battery power source 13 includes, for example, n cells 131.
.. 13n, and the deterioration state of each of the cells 131 to 13n is monitored by the deteriorated battery detection circuit 12.

The electric vehicle 11 has a drive mechanism in which the torque of a motor 14 is transmitted to wheels 16 serving as drive wheels via a transmission 15, and the output power from the assembled battery 13 is supplied to the motor 14 by an inverter. It is configured to be supplied via 17. Then, a clamp-type current sensor is connected to the power line 18 that supplies an output current from the battery pack 13 to the inverter 17.
The current sensor 19 is selectively mounted.
Is configured to measure the discharge current from the battery power supply 13 and to input the measured output to the deteriorated battery detection circuit 12.

Here, for example, clip-type measurement lines 201 to 20n are selectively connected to the positive terminal and the negative terminal of each of the series-connected cells 131 to 13n constituting the battery power supply 13. . The measurement lines 201 to 20n are respectively connected to the measurement terminals 211 to 21n set in the deteriorated battery detection circuit 12, and the measurement lines 201 to 21n are respectively connected to the measurement lines 201 to 21n.
n is composed of, for example, a wire bundle, and
The terminals are clip-connected to the terminals 1 to 13n. In the figure, the order of battery connection and the order of the measurement terminals 211 to 21n are specified, but in reality, the mutual relationship is set at random.

The number of cells 131 to 13n of the assembled battery constituting the battery power source 13 mounted on the electric vehicle 11 is as follows.
Varies by model. Therefore, the number of measurement terminals 211 to 21n set in the deteriorated battery detection circuit 12 and the measurement lines 201 to 20
The number n is set corresponding to the expected number of cells of the assembled battery.If the actual number of cells is less than the expected number of cells, the measurement will not be connected to the cells. Terminals also exist. The terminals set to the measurement lines 201 to 20n are clip-shaped and are easily connected to the battery terminals, and are connected to the battery terminals so as not to cause a problem such as electric shock. Except for the part, it has an insulating structure.

In the deteriorated battery detection circuit 12, a measuring terminal
Select terminals 221 selectively connected to 211 to 21n
And 222, measuring terminals 211 to 21n and selection terminal 221
And 222 constitute a switch 23. The switching device 23 is designed to be freely switched and controlled, and selection terminals 221 and 222 are connected to the positive and negative inputs of the voltage converter 24, and between the selection terminals 221 and 222. Is connected to a resistor 25. That is, the measurement terminal 21
The voltage between the selection terminals 221 and 222 arbitrarily selected and connected to 1 to 21n is converted into voltage data in the voltage converter 24.

The voltage information measured by the voltage converter 24 is supplied to the current converter 25 to which the measured current value from the current sensor 19 is supplied.
Is supplied to the calculation / determination unit 26 together with the current value data from
The display 27 is driven for display by the output from the calculation / determination unit 26.

The operation of detecting the deteriorated battery of the thus configured apparatus will be described with reference to FIGS. First, prior to this deteriorated battery detection operation, step 10 in FIG.
As shown by 0, each of the cells 131 to 13n of the battery power supply 13 is fully charged by a charging mechanism (not shown) set in the electric vehicle 11. Then, as in step 101, the clamp type current sensor 19 is connected to the output power line of the battery power supply 13.
At the same time, the clamps are clamped to 18, and the clips of the measurement lines 201 to 20n are connected to the terminals of the cells 131 to 13n.

As described above, the current sensor 19 is connected to the battery power supply 13.
Is set, and the measurement line is set for each of the cells 131 to 13n.
When 201 to 20n are connected, the deterioration detection operation of step 102 is started. In this deterioration detecting operation, first, the switch 23 is operated and the selection terminals 221 and 222 are set to 1 level.
The connection is set to the nth measurement terminal 201 and, for example, the nth measurement terminal 20n. Then, the voltage measurement between the first measurement terminal 201 and all the other measurement terminals in step 103 is sequentially performed in the voltage converter 24.

That is, in this step 103, the deteriorated battery detection circuit 12 is operated, and the switch 23 is operated in accordance with an instruction from the calculation / judgment unit 26 to select the selection terminals 221 and 222.
Are connected to the second measuring terminal 212 (the negative terminal of the voltage converter 24) and the first measuring terminal 211 (the positive terminal of the voltage converter 24), respectively, and the voltage between the measuring terminals 211 and 212 is connected. Is measured by the voltage converter 24. Calculation / judgment unit
In 26, the measuring terminal 211 connected to the voltage converter 24
The open terminal voltage at the time of full charge of the cell 131 between the cells 212 is input, and the measured voltage value is measured data (V1-2
).

Next, in response to an instruction from the arithmetic / judgment section 26, the measurement terminal 211 is left as it is, and the third measurement terminal 213 is switched so as to be connected to the selection terminal 221. That is, the measurement terminal 213 is connected to the positive side of the voltage converter 24. In this state, the first measurement terminal 2
The voltage between 11 and the third measurement terminal 213 is measured. Then, the measured voltage data (V1-3) is stored. Thereafter, the selection terminal is connected to the positive side of the voltage converter 24 in sequence.
221 is sequentially switched to the subsequent measuring terminals 214 to 21n,
Measurement voltage data (V1-2, V1-3, V1-4,...) Between the second measurement terminal 211 and each of the other measurement terminals is measured and stored.

In step 104, based on the measured voltage data, the cells 131 constituting the battery power supply 13
The number of 個数 13n is determined. Since the resistor 25 is connected between the selection terminals 221 and 222 at the time of the switching operation of the switch 213, the voltage measurement data at the measurement terminal to which no cell is connected due to the action of the resistor 25 is obtained. It becomes 0V. Therefore, the calculation / determination unit 26 counts the number of cells constituting the power supply battery 13 by counting the number of voltage measurement data other than 0V. The calculation / determination unit 26 determines that the voltage measurement data of the measurement terminal for which the voltage measurement data is determined to be 0 V is invalid, and erases the corresponding voltage measurement data.

In step 105, the connection order of the cells connected to the measurement terminals is determined based on the stored measured voltage data. That is, since all the stored measured voltage data are based on the voltage value detected at the first measurement terminal 211, this first measurement terminal
By comparing the measured voltage value between 211 and each of the other measuring terminals 212 to 21n, each measuring terminal 211 to
The connection states of the cells 133 to 13n respectively connected to 21n can be determined as follows.

That is, when the measured voltage data (V1-k) is a positive voltage, the cell connected to the k-th measurement terminal 21k has a higher potential than the cell connected to the first measurement terminal 211. Is the cell connected to the higher one, (V1-k
) Is a negative voltage, the k-th voltage measurement terminal 21k
Can be determined as a unit cell connected to a lower cell than the unit cell connected to the first measurement terminal 211. Therefore, measurement terminal 211 and other measurement terminals 21
The result of arranging the respective voltage measurement data between 2 and 21n in the order of the size is the same as the connection order of the unit cells connected to the respective measurement terminals and the assembled cells connected in series.

That is, the arithmetic / judgment unit 26 arranges a plurality of stored voltage measurement data in the order of magnitude, and determines the order of the number of the measurement terminal corresponding to each of the voltage measurement data by the cells 131 to 131. Store as 13n connection order. This order is used as a connection order in the assembled battery of the cells 131 to 13n to which the measurement terminals 211 to 21n are connected, and is used in the subsequent calculation determination processing.

More specifically, if the stored voltage measurement data is ranked as "V1-k <... <V1-1 <V1-j <... <V1-m", each cell is The order corresponding to the unit cell connection order of the connected measurement terminals is “k,..., 1, j,.
m ”.

The cell constituting the power supply battery 13 in this manner
If the connection order of 131 to 13n is determined, the switch 23
In step (1), the measuring terminal to which each of the unit cells 131 to 13n is independently connected can be determined. In step 106, the open terminal voltage of each of the unit cells 131 to 13n at the time of full charge is measured and stored.

More specifically, the measurement terminal determined to have the lowest potential is connected to the negative side of the voltage converter 24 according to an instruction from the calculation / determination unit 26, and the measurement terminal determined to have the second lowest potential is measured. Connect the terminal to the positive side of the voltage converter 24.
In the calculation / judgment unit 26, the first measurement terminal and the second measurement terminal
The voltage value between the second measuring terminal and the second measuring terminal is read from the voltage converter 24 and stored as the open terminal voltage (U1) of the unit cell having the lowest potential among the power supply batteries 13 composed of assembled batteries.

Next, according to an instruction from the calculation / judgment unit 26, 2
The measurement terminal that is determined to have the lowest potential is
And the third measuring terminal whose potential is determined to be the lowest is connected to the positive side of the voltage converter 24, and the voltage between the second measuring terminal and the third measuring terminal is measured. Measure. Then, this measured voltage value is stored as the open terminal voltage (U2) of the second lowest unit cell in the assembled battery. Thereafter, similarly, by sequentially switching the measurement terminals according to the voltage order, the open terminal voltages of the cells 131 to 13n at the time of full charge are measured, and the open terminal voltages of the n cells (U1, U1,. Un-1).

In step 107, a first determination step is executed based on the stored data. It is known that the open terminal voltage of a fully charged battery is proportional to the specific gravity of the electrolyte of the battery, and therefore, based on the open terminal voltage corresponding to each cell, The first step of determining the deterioration of each battery is executed.

That is, the open terminal voltage (U1
, U1,..., Un-1) are compared with a standard value (specified voltage) corresponding to the open terminal voltage of a normal cell, and the cell showing an open terminal voltage lower than this standard value is degraded. It is determined that there is a high possibility that the battery has been degraded, and in step 108, data (Uj,..., Uk) of the open terminal voltage of the unit cell determined to have the possibility of this deterioration is stored. When such a first determination step is completed in the calculation / determination section 26, the display 27 indicates that the first step of the degradation determination is completed.

When the open-circuit terminal voltage at the time of such full charge of each unit cell is measured and the first step of judging a possibly deteriorated unit cell is completed, FIG.
Proceed to step 110 of. In this step 110, the first judgment
A cell which is highly likely to deteriorate and is identified in the step is selected, and the switch 23 is operated so that the measurement terminal connected to the electrode unit of the selected cell is selected.
Accurate battery deterioration cannot be determined only by the deterioration determination based on the open terminal voltage. Therefore, the following discharge test is performed based on the determination result of the first determination step.

That is, in step 111, the drive wheels of the electric vehicle are jacked up so as to be freely rotatable, and after setting the rotatable state of the motor 14, which is the drive source, the drive motor 14 is operated. , Battery power
13 is set to the discharge state. Then, at step 112, a battery power supply for operating the drive motor 14 is provided.
The discharge current from 13 is measured by the current sensor 19.

That is, the current converter 25 measures the output from the current sensor 19 in accordance with the specified sampling timing and monitors the current value in response to a command from the calculation / judgment unit 26. This is for determining whether or not the measured current value i is between the measurement lower limit value and the measurement upper limit value. For example, the rotation speed of the motor 14 is controlled by an accelerator operation or the like, and is measured by the current sensor 19. The discharge current value from the battery power supply 13 is set to fall within a predetermined set value range.

If it is determined in step 113 that the discharge current value is not within the set range, step 114
To determine the end of the set time. If the set time is not over, the process returns to step 112. If it is determined that the set time is over, the process proceeds to step 115, where a retest is displayed and the process returns to step 110.

If it is determined in step 113 that the discharge current value i is within the set range, the flow advances to step 116 to measure the terminal voltage of the unit cell at this time. Specifically, if it is determined in the first determination step that the data of the unit cell having a high possibility of deterioration is Uj, the j-th measurement is performed in step 116 when measuring the open terminal voltage for each measurement terminal. Switch the measurement terminal that is determined to have low voltage to
By driving 23, it is connected to the negative side of the voltage converter 24, and the measurement terminal determined to have the (j + 1) th lowest voltage is connected to the positive side of the voltage converter 24.

In such a state, the voltage value converted by the voltage converter 24 is determined by j in the assembled battery constituting the battery power source 23.
Cell with the lowest potential (cell with the highest possibility of deterioration)
Is stored as the battery voltage Wj at the time of discharging. This is the terminal voltage of the unit cell when the unit cell having a high possibility of deterioration discharges a current within the range of the specified value.

In step 117, it is determined whether or not the measurement of the terminal voltage at the time of discharge of the cell having a high possibility of deterioration has been completed. If it is determined, the process returns to step 110. In other words, if there is a plurality of cells likely to be deteriorated, specify the next cell likely to be deteriorated,
23 is operated, and similarly, the terminal voltage at the time of discharging the unit cell is measured and stored.

If it is determined in step 117 that the measurement of the terminal voltage at the time of discharging the unit cell having a high possibility of deterioration has been completed, the process proceeds to step 118 to indicate that the discharge test has been completed.
The display is made at 27, and the drive motor 14 is stopped at step 119. Then, the process proceeds to the second determination step of step 120.

In the second step of the determination, the voltage drop of each cell due to the difference between the open terminal voltage at the time of full charge and the terminal voltage at the time of discharge measured so far is compared with a set specified value. In each of the cells determined to have a high possibility of deterioration in the first determination step, a voltage drop due to the discharge is obtained based on the terminal voltage at the time of discharge, and is compared with a specified value. If it is determined in step 120 that the voltage drop is smaller than the specified value, a display indicating that there is no deteriorated battery is displayed in step 121. And
When it is determined that the voltage drop is larger than the specified value,
Proceed to step 122 to determine that the battery is deteriorated,
Displays the measurement terminal to which the deteriorated battery is connected.

In the embodiment, the range of the voltage input to the voltage converter 24 is fixed. However, if the input voltage range is switched in accordance with the voltage range to be measured, more accurate voltage measurement can be performed. It is possible, and the detection accuracy of the deteriorated battery is further improved.

[0040]

As described above, according to the battery pack deterioration detecting device of the present invention, for example, in a battery pack composed of a plurality of cells mounted as a power supply device in an electric vehicle, it can be easily used in a derailleur or a maintenance shop. Deteriorated batteries can be detected.Especially, the inspection of assembled batteries in the on-board state can be easily performed without considering the number of cells and the connection status that differ for each vehicle. Simplified.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an apparatus for detecting a deteriorated battery of a battery pack according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a flow of a deteriorated battery detection processing operation of the embodiment.

FIG. 3 is a flowchart illustrating a flow of a processing operation following the processing in FIG. 2;

[Description of Signs] 11 ... Electric vehicle, 12 ... Degraded battery detection circuit, 13 ... Power supply battery by assembled battery, 131 ~ 13n ... Single cell, 14 ... Motor, 15 ...
Transmissions, 16 wheels, 17 inverters, 18 power lines, 19 ...
Clamp type current sensor, 201 to 20n… Measurement line, 211 to 21
n ... Measurement terminal, 221, 222 ... Selection terminal, 23 ... Switch,
24: voltage converter, 25: current converter, 26: calculation / judgment unit,
27… Display.

Claims (2)

(57) [Claims] 1. A current detecting means which is set on a power line output from an assembled battery constituted by a plurality of arbitrarily connected single cells and measures an output current from the assembled battery flowing through the power line; Assigned to each terminal of each cell that constitutes the battery
It is composed of multiple lead terminals that are
A plurality of measuring terminals, selection means for selecting an arbitrary measuring terminal among the plurality of measuring terminals, to measure the voltage through Therefore selected measurement terminal to the selecting means, one measurement specified Terminals and others
Measure the terminal voltage between each of the measurement terminals
The connection order of each of the plurality of cells is determined based on the fixed value.
Judgment, and based on the judgment result, open each cell.
Voltage measurement means for measuring a terminal voltage release, the open terminal voltage of the fully charged the plurality of cells constituting the pre Symbol assembled battery, a full charge when the terminal voltage measuring means for measuring and storing by said voltage measuring means, Current value determining means for driving a load connected to the battery pack, measuring a discharge current from the battery pack with the current detecting means, and determining that the current value is within a set range; in a state in which the discharge current is determined within the set range from the assembled battery at decision state, the discharge time the terminal voltage of the previous SL each cell, the discharge time of the terminal voltage measuring means for storing measured by the voltage measuring means comprising a, each said stored full charge when the terminal voltage and the discharge time of the terminal voltage, as compared to the set specified voltage, deterioration battery based on the comparison result, characterized in that it has to be identified set Battery deterioration Battery detection Location. 2. The voltage measurement device according to claim 2, wherein the plurality of measurement terminals are configured by a plurality of randomly derived lead terminals which are arbitrarily clipped and connected to respective terminal portions of each cell constituting the battery pack. The means may be the one measurement specified above.
The terminal voltage between the fixed terminal and each of the other measurement terminals
Measure, and based on the measured value, each of the plurality of cells
In order to determine the connection order of
Including arithmetic means for judging the order of size
3. The device for detecting a deteriorated battery of an assembled battery according to claim 1.